2.7, strange engine noise, please assist.

[winaje]

Hi all, I have noticed a strange noise which I think is coming from the front of the motor on my MY09 D3. I'm worried about the "clonk" sound.

Can I please ask that you watch/listen to the video and try to help me diagnose it so that I have an idea what it is? Car is due for timing belts etc ASAP also.

https://youtu.be/rpYtDx22_iE

Yes, I know the engine bay needs cleaning, too.

[rar110]

Gday Will

I can't really hear the noise. However, with your km maybe a bearing eg bottom end bearing, turbo bearing or alternator bearing. The noise can sometimes be identified but putting a long screw driver on the suspect component and your ear to the handle.

[winaje]

Have added another video, this time with the shroud removed. The sound I'm worried about is more prominent this time, hope you guys can hear it...

https://youtu.be/eLYLA0GOzlc

[Graeme]

You could remove the serpentine belt and run the engine for a few seconds to determine if the noise still occurs.

I assume its the rattly noise that concerns you.

[shanegtr]

I while ago my engine got a bit rattly - turned out the serpentine belt tensioner had failed, and it wasn't the bearing that failed either. The tensioner split in two around its tensioner spring, very nearly lost the belt because of it

[winaje]

You could remove the serpentine belt and run the engine for a few seconds to determine if the noise still occurs.

I assume its the rattly noise that concerns you.

Yeah that's what I'm going to do thanks Graeme. Yes it's the clonking rattle that I'm concerned about. It's gotten worse over the last couple of weeks.

[winaje]

I while ago my engine got a bit rattly - turned out the serpentine belt tensioner had failed, and it wasn't the bearing that failed either. The tensioner split in two around its tensioner spring, very nearly lost the belt because of it

Thanks Shane, interesting you should mention the tensioner. It seems to me that the lower tensioner is on a significant angle, tilting back towards the block. So much so that the belt seems to be twisted out of straight onto an angle as it goes over the tensioner. Was yours like that?

[shanegtr]

exactly like that - didn't think of taking a photo at the time either

[winaje]

Well, it's just gotten a whole lot worse. Started ticking on the freeway near Benalla on Friday, pulled over asap. Had to get flat-bedded home, tensioner totally destroyed. However, with tensioner and serpentine belt removed, it's making a terrible noise, and won't run.

https://youtu.be/2Hz9FiT42jA

[SBD4]

Will, I might be mistaken but, should you be trying to start the engine without the belt in place? I thought that would be akin to having the webbing on the oil pump fail with fatal damage to the engine.

[BigJon]

Serpentine belt just runs accessories (P/S, A/C, etc) and water pump. No drama to run the engine for a short time with it not fitted.

[Graeme]

I can't guess at the cause of the noise.

Did the engine stop by itself or did you switch it off and if switched off, what noises was it making and was the serpentine belt still turning, perhaps as evidenced by having power steering?

Has the timing belt been changed?

Is the serpentine belt tensioner bracket still intact?

Is the crankshaft pulley still tight?

[winaje]

I can't guess at the cause of the noise.

Did the engine stop by itself or did you switch it off and if switched off, what noises was it making and was the serpentine belt still turning, perhaps as evidenced by having power steering?
In the video the engine turned off by itself. When the problem occurred on the road I turned it off, everything was still running.


Has the timing belt been changed?
Changed at 168k service, it's about 10k overdue for it's next one (345k)


Is the serpentine belt tensioner bracket still intact?
Tensioner was totally wrecked, falling apart in my hands. The video shows the noise with the tensioner and belt removed though.


Is the crankshaft pulley still tight?
Yes

Thanks for replies.

[Graeme]

If there's been a timing belt mishap then the failing to keep running could be due to a camshaft timing fault but I would expect to see an engine fault.

Is the noise emanating from the front or further back?

How's the HPFP belt?